Improvement in sun-dials



UNITED STATES PATENT OEEIGE.

GEORGE MEHR, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN SUN-DIALS.

Specification forming part of Letters Patent No.155,327, dated September 22, 1874; application filed May 22, 1874.

description of the same, reference being had Y to the accompanying drawing, forming a part of this specification, in which- Figure l is a perspective view 5 Fig. 2, a side, and Fig. 3 a front, elevation.

The invention relates to a novel construction and notation of dial, by which the correct time of day may be exhibited by the sun in a position inclined toward, and convenient to, the passer-by on the streets and thoroughfares of cities and towns, enabling all, without dificulty or delay, to perceive the solar time.

A represents a cross iitted in a suitable socket, block, or bracket, and inclined at such an angle to a horizontal plane as corresponds with the degree of latitude in which the locality of the dial may be situated. B O D E are the four arms of cross, of which the three former are provided with hemispherical concavities B' O' D', quadrautally divided by partitions b c d.

As the sun rises, the division b will throw a shadow on the left side of concavity B', and the arm B on the right side ot the arm C. This will graduallyr withdraw,on the scales c1 bl, in the direction of the division b and the intersection of arms C B until six o'clock,

when it will disappear. Reappearing on the right of division b and the left of division c, it will advance up the scales b2 c2 e3, and, after nine oclock, up the sca-le d2, until the sun attains its meridian, when all shadows will again disappear. As the sun declines, the shadow of division c d and of arms D O will pass over the sca-les or dials o3 d3 e3 b3. At six oelock the shadow will again momentarily disappear, and then, resuming its course, pass over the dial-scales c4 d4.

It will be observed that the dial-scales cl d2 e2 b3 e3 c4 are fractional, and together make up the days notation, while the two opposite concave scales make a perfect dial, and the middle-arm scale (side and concave) another.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. A sun-dial made iu the shape of a cross, B O D E, having partitioned end concavities B' C' D', in three of the arms, and a system of timescales, b1 c1 b2 c2 d2 e2 b3 c3 d3 c3 c4 d, arranged as shown and described.

2. Adial having' three concavities on the ends of cross-arms, with diametrical partitions, arranged and notated as and for the purpose specified.

GEO. MEHR.

Witnesses:

SoLoN C. KEMON, EDWD. BENTON. 

